Device for individual control of knitting yarns



Dec. 30, 1941. A. KRASA 2,268,039

DEVICE FOR INDIVIDUAL CONTROL OF KNITTING YARNS Filed Aug. 10, 1939 5 Sheets-Sheet 1 A. KRASA Dec. 30, 1941.

DEVICE FOR INDIVIDUAL CONTROL OF KNITTING YARNS Filed Aug. 10, 1939 5 Sheets-Sheet 2 INVENTOR.

A. KRASA Dec. 30, 1941.

DEVICE FOR INDIVIDUAL CONTROL OF KNITTING YARNS 5 Sheeis-Sheet 3 Filed Aug. 10, 1939 Dec. 30, 1941. KRASA 2,263,039

DEVICE FOR INDIVIDUAL CONTROL OI KNITTING YARNS M ,1 6 Y 24 a J 45 IN VENT OR.

Dec. 30, 1941. KRASA 2,268,039 DEVICE F OR INDIVIDUAL CONTROL OF KNITTING YARNS Filed Aug. 10, 1939 5 Sheets-Sheet 5 a; M a:

Patented Dec. 30, 1941 umreo STATES arcane DEVICE FOR INDIVIDUAL CONT 15 Claims.

My invention relates to improvements in knitting machines, more especially circular machines for knitting tubular material having a plurality of cylindrical stripes knitted from yarns selected for the purpose. The objects of the invention are, first, to pinch each yarn in an individual device after it is removed from the knitting needles; second, to sever each yarn after it is pinched from the knitted material; third, to operate each yarn pinching device by the same pattern chain which operates the fingers guiding their respective yarns to and out of the needles; fourth, to provide a simple and compact pinching and severing device which will occupy small space and be accessible; fifth, to provide a more direct operating mechanism for the yarn guiding fingers.

Similar numerals indicate similar parts throughout the drawings.

I attain these objects by mechanism illustrated in the accompanying drawings, in which- Figure l is a plan view of the improvement applied to a Leighton machine for knitting stockings. The knitted material held up by the horizontal needles is conventionallyillustrated herein and in Fig. by entwining a yarn between and about the horizontal and vertical needles;

Fig. 2 is a front elevation view of the improvement. The yarn guiding fingersand their respective operating mechanisms are not illustrated for the sake of clarity. The cam plate, needle plate, and base plate are illustrated in cross section Fig. 3 is a side elevation view. The yarn pinching and severing devices are not illustrated. A section of the pattern chain and its operating mechanism is shown in this view only;

Fig. 4 is an enlarged elevation view of the yarn pinching and severing devices and the yarn guidmg fingers. The hatch work about the vertical needle cylinder conventionally illustrates the knitted material. The view clearly illustrates the yarns as they appear in Fig. 1;

Fig. 5 is a plan view along the line 5-5 in Fig. 4;

Fig. 6 is an elevation view along the line 6-6 in Fig. 5. It illustrates an operable shearing blade moved into position for engaging a yarn to be pinched and severed. The bracket for slidably supporting the bar holding said blade is illustrated broken away;

Fig. 7 is a bottom view of the pinching plate and shearing blade holders, drawn along the line 1-1 in Fig- 4;

position.

Fig. 8 is a view of the operable blade and its supporting bar illustrated in Fig. 6;

Fig. 9 is an elevation view along the line 9-9 in Figure 3. illustrating the ratchets for operating their respective shearing blades to up-position by the oscillating shafts shown in cross section. Wall i2 is broken away to clarify the view;

Fig. 10 is a view of Fig. 9 illustrating the ratchets lifted out of engaging contact with their respective operating bars by a rod shown in cross section:

Figures ll, 12 and 13 are side views of the bars which control the movements of their respective fingers to non-knitting position and control the movements of their respective yarn pinching blades to lip-position;

Fig. 14 is a view along the line ld-Jt in Fig. 1, illustrating the finger operating mechanism; and

Fig. 15 is an enlarged plan view of the pawls G0 and GI and their relative positions with the lateral projections 55 and 55 as illustrated in Fig. 1.

Usually there are provided two sets of yarn guiding fingers and yarn pinching and severing devices on the machine illustrated. The sets are suitably spaced apart. Since the sets are alike, only one is illustrated and described.

A brief description of the Leighton machine for knitting a three-color stocking follows:

In the specification and claims the phrase or its like, to inner position, describing the movement of a part or parts, such as the pawl disengaging bars and the blade operating ratchets, from one position to another is to be construed as that position which is toward the central opening of the machine. To outer position, is in opposite direction from inner position.

The base plate 2 is rigidly held at a convenient height by legs 3 secured to the floor. Only two of the legs, broken off, are illustrated. The needle plate 4, having a plurality of suitably spaced slots radially out on its top surface for supporting the horizontal needles, is securely clamped to the base plate. The needles are controlled by a cammed raceway provided in the bottom side of the cam plate 5 which is rotatably supported by the needle plate. Each of the above said plates are circularly shaped and in their assembly are concentrically positioned. Each plate is provided with a central opening through the center of which a vertical shaft 6 penetrates. A bracket I screwed to the top of the cam plate 5 at diametrically opposite sides holds the shaft rigidly in At the lower end of the shaft is secured a cylindrical cam plug 8 for operating and corn trolling the vertical needles by a race-way provided in the cylindrical surface. The vertical needles are supported in slots cut in the inner surface of a cylinder 9 which is loosely fitted to the cam plug. The end of the shaft 6 extends beyond the bottom of the cam plug. A cupped disc I loosely fitted over the shaft extension supports the cylinder 9 vertically. A collar H secured to the shaft supports the disc in position. Known means prevent the rotation of the cylinder by frictional contact with the cam plug. The ring l2 supported by the needle plate takes the wear of the needles, moving into and out of knitting action under the strain of the pulling device, not illustrated.

Along the periphery of the cam plate is a downwardly extending rim which is flanged outwardly at its bottom. A plurality of blocks l3 screwed to the base plate 2 slidably overlap the upper surface of the flanged section to prevent upward movement of the cam plate 5.

Gear teeth l4 are cut in the bottom side of the flanged section, by which the cam plate 5 and the cam plug 8 are rotated. A power driven gear, not illustrated, meshing with the said gear teeth drives the machine. A gear l5 driven by the teeth l4 operatesa speed reduction umt l6 which in turn revolves an eccentric H at a ratio of one revolution for each revolution of the cam plate 5. The gears are illustrated by their pitch circles with a few teeth drawn in, Fig. 3. A pawl l8 operated by the eccentric drives a ratchet wheel l9 with a step .by step movement. This movement is applied to a sprocket 20 which drives an endlesspattern chain. The pattern chain consists of the high links 2|, the medium links 22, and the low links 23. Each kind of link represents a designated colored yarn to be knit. The length of the chain controls the length of the stocking and the length of a designated color of yarn in the knitted stocking is determined by the number of links controlling the said color.

The vertically movable rod 24 supported by the base plate 2 is adapted to engage the links of the pattern chain. The pattern cam 25 having the guide bar 25, is rigidly secured to the upper end of rod 24. The said cam is moved upward by the links and downward by gravity. It is thus seen that the pattern cam moves to three positions, each of which is determined by the link engaged by rod 24.

The improvement including re-designecl known mechanism will now be described:

The levers 21, 28 and 29 are preferably positioned to pivot on a vertical pin 30, held by the support 3|, which is rigidly fastened to the cam plate 5. Springs 32, 33 and 34 resiliently press the levers against their respective stops 35, 35 and 31. The stops are preferably adjustable screws supported by 3. lug 38 provided on the support 3|. After adjustment the screws are se cured in position by set screws.

In the rotation of the cam plate 5, each lever is moved through a predetermined angle by engagement with the pattern cam 25 when the cam -is moved to a position on a plane with the lever and each lever, when engaged by the said cam, is held against return movement after it is moved out of engagement with the cam. This will be explained later.

The yarn fingers 38, 40 and are provided with eyes at their bottom ends, through which are threaded their respective yarns 42, 43 and 44 respective levers 21, 28 and 29. When a lever is operatively engaged by cam 25, the finger operated by it guides its yarn in position above the horizontal needles which are moved in position to receive said yarn by the cam plate 5. The previous stitches held by the needles are cast off in the return movement by passing over the latched hooks in known manner. A well known yarn guide guides the feedingyarn to a plane within reach of the hooks on the needles to prevent skip stitches. The manner in which the vertical needles receive their share of the feeding yarn is also well known.

Provided on the levers are lateral projections 53, 54 and 55 in which notches 56, 51 and 58 respectively, are machined to receive pawls 59, 50 and 6| pivoting on pin 62 which is securely held by the support 3|. The pawls are resiliently pressed into their respective notches by their respective springs 32, 33 and 34 when the said levers are moved singly through a predetermined angle by engagement with the pattern cam 25, thereby preventing the return of the levers to their previous positions. The notches are further adapted to check the movement of the pawls after entering same. See Fig. 1, pawl 60, notch 51 on projection 54.

Springs 32, 33 and 34 are respectively hooked to extension pieces 63, 64 and 65.which are secured in a suitable manner to their respective pawl operating arms 66, 61 and 68. The arms are preferably integral with the pawls 59, 60 and GI as illustrated in Fig. 1. At their other ends the springs are hooked in suitable manner to their respective levers 21, 28 and 29 to press the latter against their respective stops as described in the foregoing.

Pawl disengaging bars 69, 10 and 1| for disengaging their respective pawls 59, 60 and 6| from their respective levers are slidably supported by the support 3| between the Walls 12 and 13.

Plates shaped to the contour of the walls are screwed to the latter to keep out. yarn lint. Strips 14 and 15 bent at right angles and screwed to wall 13 prevent upward movement of the bars.

Recesses 16, 11 and 18 machined near the inner ends of the bars receive the disc-like ends 19, and 8| of their respective pawl operating arms 66, 61 and 68. The arms are stepped in their lengths to connect with their respective bars. The bars are operated to their outer positions by their respective pawl operating arms when the latter are actuated by their respective springs 32, 33 and 34. The outer end of each bar is adapted to engage pattern cam 25 in only two of its three positions after each bar is operated to its outer position by its respective pawl operating arm. Machined in the outer end of each bar on a plane with its respective lever is a recess sufficiently large to clear the pattern cam when the bar is in its outer position. The purpose of the recess follows: When a lever is operatively engaged by the pattern cam 25 to bring its respective yarn guiding finger into knitting position, its respective pawl engaging said lever to keep the finger in said position after the lever has passed.

out of engagement with the pattern cam, is undisturbed by its respective pawl disengaging bar because of said recess when the latter is moved by the cam plate past the pattern cam. Because of it, knitting with the yarn guided by said finger continues until the cam moves to one of its other two positions, in either of which the bar is engaged by the pattern cam. By such engagement the said pawl is moved out of the notch in the lateral projection of said lever, thereby permitting the lever to return to its stop. The movement of said lever returning to its stop operates the finger which guides thesaid yarn, to a non-knitting position, below the horizontal needles. In the interval of knitting with the aforesaid yarn, the other two bars are held to their inner positions, out of engaging contact with the cam 25, in a manner which will be described:

When a bar (either 69 or III, or ll) is engaged by cam 25 it moves its respective pawl out of the notch machined in the lateral projection provided on its respective lever. When this occurs, the

lever is quickly moved against its stop by its re- I spective spring (either 32, or 33, or 34). By the same spring the said pawl is pressed into contact with the machined surface 82 on the lateral projection. Because of the positive operating connection between the bar and the arm operating the pawl, the bar is held to its inner position by said contact until its respective lever is again operated by the pattern cam. See Figure 1, pawl 59, lateral projection 53. Each lateral projection is machined with a surface 82.

The three oscillating shafts 83, 84 and 85 are supported in bearings provided in wall I2 and in the end of the bracket 86 which is rigidly fastened to wall I2. End motion of the shafts are controlled by collars 8'I and by the ratchet carrying arms 88, 89 and Ill] respectively, which are pinned to the shafts.

Ra-tchets SI, 92 and 93 are pivotally supported at the bifurcated ends of said arms. Each ratchet is pressed into a recess machined in the top side of its respective pawl disengaging bar when the latter is moved to its outer position. The end surfaces 94 of said recesses engage the ratchets when the bars are moved inward singly by cam 25, thereby oscillating their respective shafts in one direction. Springs 95 resiliently press the ratchets into said recesses. The springs are hooked between a common pin 96 secured to wall 12 and pins 9'! secured to each ratchet. See Fig ure 9. Since there is always one pawl disengaging bar in outer position in the interval of knitting a stripe, its respective ratchet (either Ill, or 92, or 93) is in position to be engaged when said bar is moved inwardly by thesaid cam. The other ratchets are in pressing contact with the top side of the other bars which are held to their inner positions. Figures 11, 12 and 13 illustrate the shape of the bars.

Blade operating levers 98, 99 and let which are clamped to their respective shafts B3, 84 and 85, are resiliently pressed against their respective shafts 83, 84 and 85, are resiliently pressed against their respective stops IIlI, IE2 and I03 by the springs I04. The springs are hooked between eyes provided in lugs I05 on their respective levers and eyes provided in a plate M16 which is fastened to a rod Ill! secured to bracket 86. The springs oscillate their respective shafts in reverse direction from that by the ratchets 9|, 92 and 93. The stops are preferably adjustable screws locked by nuts I08 and are supported by a lug I09 extending from the bearing end of bracket 86.

Bell cranks IIII, III and IIZ pivoting on a stud I I3 which is fixed in position on bracket I I4, are operated from their respective levers 98, 99 and I00 by the connecting links H5, H5 and Ill. The other arms of the ball cranks are connected to their respective blade operating bars H8, H9 and I2!) by the links I2I, I22 and I23 respectively. Because the operating plane of the blade bars is different from that of the bell cranks, the upper ends of the blade bars are twisted to bring the axes of the pivots for said links in alignment with those of the bell cranks.

The blade operating bars IIB, H9 and I20 are slidably supported in slots vertically machined in a finished surface of the bracket I24 which is tightly fastened to bracket I25, which in turn is rigidly secured to bracket I. A cover plate 26, screwed to bracket I24, completes the enclosure of the bars in their respective slots. To the upper end of bracket I24 is rigidly secured the bracket M4 for supporting the bell cranks. The bottom end of bracket I24 is machined to receive the holders I21, I28 and I29. Figure 7 illustrates the screws holding them securely in position on the bracket and the relative lengths of the holders.

Near the exposed end of each of said holders a seat is machined on its vertical side to receive one of the vertical shearing blades I30, I3I and I32. Opposite to said seat another seat is machined on the same plane on each of said holders to receive one of the yarn pinching plates I33, I34 and IE5. Each blade and its respective pinching plate are firmly secured to its respective holder by a screw I35. Each blade has a horizontally disposed, sh'ear cutting edge at its top end, above which the pinching plate extends a suitable distance.

The vertically movable blades I31, I38 and I3Q are secured to the blade operating bars H8, H9 and I20 respectively. They operate between the fixed shearing blades and their respective pinching plates and preferably in frictional contact with both. The shear cutting edges I3'I--A cooperate with the cutting edges of their respective fixed blades to sever their respective yarns. The blades are moved upward singly in position for engaging their respective yarns after the latter are guided singly to non-knitting position. The

upward movement of each blade is eifected by.

the engagement of pattern cam 25 with the pawl disengaging bar (either 69, I0 or 'II) controlling the downward movement of its respective finger to non-knitting position. The ratchet (either 9 I, 92 or 83) in engagement with said bar operates its respective blade upward for the purpose described. The vertical edges I3'I--B of the blades keep their respective laterally moving yarns under the cutting edges of their respective blades. Figure 6 illustrates this feature. The blades are stepped in their overall widths (from the blade operating bars to the said vertical edges) to conform with their respective pinching plate and fixed blade holders.

The mechanism for operating the blades I 31, I38 and I39 downwardly to pinch and sever their respective yarns after they are engaged in the manner described, will now be explained:

The bell crank I40 is pivotally mounted on stud I4I, screwed into wall 12. The horizontally disposed arm of said crank firmly holds a rod I42 for lifting all the ratchets SI, 92 and 93 free from their respective bars 69, Ill and II. See Figure 10. A suitable opening is provided in wall 12 to permit free movement of the said rod. The other arm of the bell crank is connected to a lever I43 which is pivotally mounted on a vertical stud I44 secured to cam plate 5. The end of the lever is bifurcated to receive slidably a cylindrical member I45 which is plvotally supported by a stud I45 fixed longitudinally on the said arm, thus providing an inexpensive universal connection between the said arm and the lever. In Figure 2 the lever is broken away at the bifurcated end which is shown in cross section. The opposite end I41 of said lever is adapted to engage pattern cam 25 in each revolution of cam plate 5. It is sufliciently wide to engage the pattern cam in any position of the latter. The engagement of lever I43 with cam 25 controls the function of pinching and cutting of a yarn which was previously moved out of knitting position. When said yarn was in knitting action its respective bar (either 69, or 10, or H) was in outer position. Its respective ratchet (either 9|, or 92, or 93) was pressed into the recess provided in said bar, in position to be engaged by the surface 94 when the bar is moved inward by cam 25. When cam 25 engaged said bar, the finger guiding said yarn moved the yarn to a position below the horizontal needles, whereby knitting of said yarn was discontinued. By the same engagement the ratchet in pressing engagement with the bar moved its respective blade upward, thereby providing an opening between its cutting edge and its respective pinching plate in which the said yarn enters after continued move ment of the cam plate 5. See Fig. 6. 'After the entrance of the yarn in said opening, the movement of cam plate brings the end I41 of lever I43 into engagement with pattern cam 25, thereby lifting the aforesaid ratchet out of engagement with said bar by the rod I42. When said ratchet is lifted, spring I04 rapidly moves the operable blade to its down position through its operating connections. In the downward movement the yarn is drawn between the blade and that portion of the pinching plate which extends above its respective fixed blade, in pinching contact between them, after which the cutting edge of the blade is moved past the cutting edge of the fixed blade, thereby severing the yarn from the knitted material. Further movement of said blade is stopped by its respective stop-(either IN, I 02 or I03) which is provided with adjustment for this purpose.

From the foregoing it is evident that each yarn has its own pinching and severing device and that each operable blade is operatively controlled by pattern cam 25, which in turn is controlled by a single pattern chain.

After the engagement of lever I43 with cam 25, a spring. I48 hooked between a, pin secured to the horizontally disposed arm of the bell crank and a pin secured to the support 3I resiliently presses the said arm against a stop I49 which is secured to said support, thereby moving lever I43 back into engaging position.

Near the operating ends of levers 21, 28 and 29, supports are provided to support them against downward spring when their respective arms 45,

45 and 41 are operated upward. A machined surface on support 3| supports lever 29. Plates I50 and I5I support levers 21 and 28 respectively. Spacers I52 in the form of collars separate the plates. Like spacers I53 separate pate II from the said machined surface. Screws penetrating the plates and spacers and threaded into the support 3| firmly hold the parts together.

Levers 21 and 29 are offset for the purpose described.

The operation of the improvement in connection with known mechanism will now be described:

Figure 3 illustrates the rod 24 carrying the pattern cam 25 as just having dropped from the high link 2| of the pattern chain to link 22 in the last movement of the sprocket 20. Since the positions of the parts involved for knitting yarn prior to the last movement of said sprocket are not illustrated, they will be described. When at first the rod 24 was operated to its high position on link 2|, pattern cam 25 operatively engaged lever 21 which lifted finger 39 to bring yarn 42 into knitting action, whereupon the pawl 59 was pressed by its spring 32 into the notch '56 to hold the lever in engaged position. Since the pawl operating arm 66 is integral with pawl 59, the movement of the pawl entering the said notch operated its respective disengaging bar 69 to its outer position. Because of the recess machined in the bar to avoid engagement with cam 25 in high position, the above parts remained in their positions as described, throughout the interval of the rod 24 riding on the high links 2I. During this interval, levers 28 and 29 controlling the yarn fingers 49 and M respectively, were pressed against their respective stops 36 and 31 by their springs 33 and 34. Pawls 60 and BI were pressed against the surfaces 82 on their respective lateral pieces of said levers. With the pawls in this position their respective operating arms 51 and 68 hold their respective bars 10 and H to their inner positions, out of engagement with cam 25. The ends of yarns 43 and 44 leading from their respective fingers 40 and M were frictionally held between their respective pinching plates I34 and I35, and their respective blades I38 and I39. The blades including blade I31 for cutting off yarn 42 when the latter is movedto non-knitting position, were in down position.

The blade operating levers 98, 99 and I00 were pressed against their respective stops I M, I02 and I03'by the springs I04, wherefore the ratchets 9|, 92 and 93 Were in their outer positions. With the bars 10 and H held to their inner positions, the ratchets 92 and 93 were pressed against the top surface of their respective bars by the springs 95. Figure 9 illustrates bar 1I and its respective ratchet 93 in this position. Bar 69 held by the arm 56 to its outer position diagrammatically illustrated in Figure 1 throughout the interval of knitting with yarn 42, was in position to engage ratchet 9I. This concludes the set-up of the parts in the interval of knitting with yarn 42.

The sprocket 20 driving the pattern chain is moved at a predetermined time in the rotation of the cam plate 5. When the rod 24 drops from high link 2I to link 22 of the pattern chain, as illustrated in Fig. 3, the pattern cam 25 is in position to engage lever 28. In the engagement of said lever, pawl 60 is pressed into notch 51 by its spring 33 to hold the lever in engaged position. The movement of the pawl operates its respective bar 10 to its outer position. Because of the recess machined in the bar to avoid engagement with cam 25, the lever 28 remains in engaged position in the continued rotation of cam plate 5 until the rod 24 moves to another position. See Figures 1, 9 and 15. At the time of engagement of lever 28, lever 21 is still held against retraction by its pawl 59. Since the levers operate the fingers 39 and 40 respectively,

aacaosc both yarns 42 and 43 are now in knitting action. In Fig. the end of yarn 43 is diagrammatically illustrated in its pinching device before it is pulled therefrom by the rotation of cam plate 5. It is identified by the numeral 43--A after it was pulled out of said device. The yarns re main in knitting action-until the cam plate 5 brings bar 69 into engagement with pattern cam 25, whereby pawl 59 is moved out of engagement with lever 27, the latter returning to its stop by the tension of the spring 32, thereby moving yarn 42 to non-knitting position. Bar 69 is diagrammatically illustrated in Fig. 1 in its outer position before engagement with cam 25. After the engagement of bar 69 with cam 25 the bar is held to its inner position by pawl 59 which is now in engaging contact with the machined surface 82 on the piece 53 provided on lever 21.

Ratchet 9! which is in position for engagement with bar 69 before the latter was engaged by the cam 25, oscillates shaft 83 when the cam moves said bar inward, whereby the movable blade I31 is moved upward through its operating connections with said shaft. The moving of the blade I31 upward against the tension of spring IE4 is done simultaneously with the moving of yarn .42 tonon-knitting position The said blade remains in its up-position until ratchet 9I is disengaged from bar 69 held at its inner position.

Yarn 42 after it leaves the needles indicated at position 42-A, Figure 5, ,draws in a straight line from its finger 39 as the latter rotates with the cam plate 5. As the distance between said position and the finger increases the angle of the line changes in a direction for the yarn to enter the space provided between the cutting edge of blade I31 in its up position and the top of its respective pinching plate I33, Figure 6. With yarn 42 in this position it is ready to be pniched and severed. This is controlled by lever I43 which is now moved by the cam plate 5 into position for its end I41 to be engaged by cam 25. By the engagement of the lever. the bell crank I holding the rod I42 lifts the ratchets 9|, 92 and 93 free from their respective bars 69, III and II.

Since the ratchet BI is held to its inner position by engagement with bar 69 against the tension of spring I 04, it follows that when the ratchet was lifted out of engagement by rod I42, the spring operated the blade I31 to its down position, carrying yarn 42 into frictional contact with pinching plate I33. Near the end of movement of said blade the cutting edge I3'I--A meets the cutting edge of the fixed blade I3I, whereby the yarn is severed from the knitted material. In the continued movement of the cam plate 5, all the operable blades remain in down position until pattern cam 25 moves to another position, when the foregoing operation is repeated.

In the claims, active finger" is defined as the finger which was operated to knitting position in the last yarn change and is in said position when a new yarn change is being effected. Operative position of an operable blade associated with a yarn pinching device is to be construed as that position which is suitable for the blade to engage its respective withdrawn yarn when the blade is reversely operated. Positive engagement as herein employed, is to be construed as an engagement wherein the parts involved remain in the same relative position throughout their operative movement, thus operating like connected parts.

Having thus described my invention, what I claim as new and desire to secure by U. S. Letters Patent is:

1. In yarn changingmechanism for a circular knitting machine, the combination of a plurality of yarn guiding fingers, means for selectively operating the fingers singly to knitting position, means for retracting the active finger, an equal plurality of yarn pinching devices associated with the fingers each having an operable blade co-operating therewith for pinching the yarnof its associated finger after the latter is withdrawn from knitting position, mechanism for operating the operable blade corresponding to the active finger to operative position, a driven member included in said mechanism which engagingly operates a second member of said mechanism in ratchet-like manner, means for breaking the engagement of said members, and means for reversely operating the blade.

2. In a circular knitting machine, the combination in yarn changing mechanism of a plurality of yarn guiding fingers each having mechanism for operating its respective fingerto knitting position, a cam having vertical movement to a plurality of varied operating planes or levels in each of which the cam operates a certain one of said mechanisms, mechanism operatively controlled by said cam for efiecting the retraction of the active finger in a yarn change, an independent yarn pinching and severing device provided for each yarn, each having an operable blade for guiding its respective yarn after it is withadrawn from knitting position, from its natural course to its respective device mechanism onerated by said cam for operating the blade associated with the active finger, to operative position, and mechanism operatively controlled by said cam for effecting the retraction of the operated blade whereby the withdrawn yarn of its associated finger is pinched and severed in its respective device.

3. In yarn changing mechanism for a circular knitting machine the combination of a plurality of yarn guiding fingers, means for selectively operating the fingers singly to knitting position, means for retracting the active finger, an equal plurality of yarn pinching devices associated with the fingers each having an operable blade cooperating therewith to pinch the yarn of its associated finger when the latter is retracted, mechanism operated by the means for retracting the active finger for operating the blade corresponding to said finger to operative position, resilient means for operating the blade reversely and means for controlling the reverse movement of the operated blade.

4. In yarn changing mechanism for a circular knitting machine, the combination of a plurality of yarn guiding fingers, means for selectively operating the fingers singly to knitting position, means for retracting the active finger, an equal plurality of yarn pinching devices each associated with a certain finger for pinching the yarns of their respective fingers after they are withdrawn from knitting position, an operable blade provided with each device for guiding the withdrawn yarn from its natural course to its respective pinching device, mechanism for operating the operable blade corresponding to the active finger to operative position, a cam having vertical movement to an equal plurality of varied planes or levels, a member included in said mechanism which is engagingly operated by said cam when the latter is moved from a predetermined plane or level, a ratchet included in said mechanism which is driven by the engagement of said member with said cam and which in turn engagingly operates a second member of said mechanism to move the blade to operative position, means for disengaging the ratchet after the blade is in operative position, and resilient means for operating the blade reversely when said ratchet is disengaged.

5. In yarn changing mechanism for a circular knitting machine, the combination of a plurality of yarn guiding fingers, means for selectively operating the fingers singly to knitting position, means for retracting the active finger, an equal plurality of yarn pinching devices each having an operable blade co-operating therewith to pinch the yarn of its associated finger after it is retracted, an equal plurality of mechanisms for operating their respective blades to operative position, a ratchet provided with each mechanism for engagingly operating a certain member of its respective mechanism, a plurality of engagingly operated second members included in said mechanisms each adapted to engage its respective ratchet in its operative movement whereby its respective blade is operated to said 25 position, a cam having vertical movement to an equal plurality of varied planes or levels in each of which the cam operates a certain one of said second members, means for controlling the vertical movements of the cam, means for disengaging the ratchet operating the blade corresponding to the active finger to said position, and means for reversely operating the blade.

6. In yarn changing mechanism for a circular knitting machine, the combination of a plurality of yarn guiding fingers, means for selectively operating the fingers singly to knitting position, means for retracting the active finger, an equal plurality of yarn pinching devices each having an operable blade co-operating therewith to pinch the yarn of its associated finger after the latter is retracted, mechanism for operating the operable blade corresponding to the active finger to operative position, means for keeping the blade in operative position against tension to retract the blade, after the operative movement of said mechanism is completed, a driven ratchet included in said mechanism which engagingly operates an associated member of said mechanism in the operative movement or the latter, means for disengaging the ratchet after the blade is in operative position, and means for reversely operating the blade when said ratchet is disens gaged.

7. In yarn changing mechanism for a circular knitting machine, the combination of a plurality of yarn guiding fingers, means for selectively operating the fingers singly to knitting position. means for retracting the active finger, an equal plurality of yarn pinching devices associated with the fingers, each having an operable blade cooperating therewith to pinch the yarn of its respective finger when the latter is retracted. a cam, mechanism engagingly operated by said cam for operating the blade corresponding to the active finger to operative position when said finger is retracted, a ratchet included in said mechanism which is driven by an associated member operated by said cam and which in turn engagingly operates a second member of said mechanism in the operative movement of the latter. means for disengaging the ratchet after the blade is in operative position, means for reversely operating the blade after the ratchet is disengaged,

inoperative position until said finger is again moved to knitting position.

8 In yarn changing mechanism for a circular knitting machine, the combination of a plural- 6 ity of yarn guiding fingers, means for selectively 1o crating therewith to pinch the yarn or its associated finger after the latter is withdrawn from knitting position, a cam, mechanism engagingly operated by said camfor operating the blade corresponding to the active finger to operative position, a driven member included in said mechanism which is adapted to operate a second member of said mechanism by positive engagement, means for breaking said engagement of the members, and means for retracting the operated blade when said engagement is broken.

9. In yarn changing mechanism for a circular knitting machine, the combination of a plurality of yarn guiding fingers, means for selectively operating the fingers singly to knitting position, means for retracting the active finger, an equal plurality of yarn pinching devices associated with thefingers each having an operable blade co-opcrating therewith for pinching the yarn of its associated finger after the latter is withdrawn from said position, an equal plurality of mechanisms for operating their respective operable blades to operative position, a cam having vertical movement to an equal plurality of planes or levels in each of which the cam engagingly operates a predetermined one of said mechanisms,

cam controlling mechanism for effecting the movement of the said cam to the plane or level to operate the operable blade corresponding to the active finger in a yarn change, a member included in each of said mechanisms which operates a second member or its respective mechanism in the operative movement of the latter, by positive engagement and which, when disengaged from said second member, renders its respective 5 blade reversely operative, means for breaking the engagement of each group of members after its corresponding blade is moved to operative position, and means for reversely operating each operated blade.

10. In a yarn changing mechanism for a circular knitting machine, the combination of a plurality of yarn guiding fingers, means for selectively operating the fingers singly to knitting position, means for retracting the active finger, an equal plurality of yarn pinching devices each associated with a certain finger and each having an operable blade to guide the withdrawn yarn of its associated finger after the latter is retracted to its respective device for pinching, an equal 0 plurality of mechanisms each for operating a cert ain blade to operative position, a driven ratchet provided in each mechanism which engagingly operates a certain member included in its respective mechanism when the latter is operated, a

cam having vertical movement to an equal plurality of operating planes or levels, a slide bar included in each of said mechanisms which is adapted to engage the cam when the latter is moved to a predetermined plane or level wherby its respective blade is operated to said position, resilient means for reversely operating each slide bar, means for controlling the reverse movement of each slide bar, and means for disengaging the ratchet associated with the slide bar in the ina d means for keeping th first a d mber i terval Said bar is under reverse control whereby its respective blade is rendered free to move reversely by tension provided therefor.

11. In yam changing mechanism for a circular knitting machine, the combination of a plurality of yarn guiding fingers, means for selectively operating the fingers singly to knitting position, means for retracting the active finger, an equal plurality of yarn pinching devices each having an operable blade co-operating therewith for pinching the yarn of its respective finger after the latter is withdrawn from said position, an equal plurality of ratchet driven mechanisms for operating their respective blades to operative position, a like plurality of engagingly operated slide bars each adapted to engage a certain one of said ratchets in the operative movement of the bar, a cam having vertical movement to an equal plurality of varied planes or levels in each of which the cam engagingly operatesa certain one of said bars, cam controlling means for effecting the vertical movement of the cam to the plane or level to operate the mechanism of the operable blade corresponding to the active finger, means for disengaging the ratchet after its associated blade is in operative position, and means for reversely operating the mechanism when its respective ratchet is disengaged.

12. The structure defined in claim 11 in further combination with resilient means for op erating each of said slide bars reversely, and means for keeping the operated slide bar operating the operable blade corresponding to the active finger in inoperative position during the interval the said finger remains in non-knitting position after its retraction, thereby preventing re-engagement with said cam.

13. The structure defined in claim 11, in further combination with means for keeping the operated slide bar operating the operable blade corresponding to the active finger, in inoperative position during the interval the said finger remains in non-knitting position after it is retracted, and means for moving the said bar to operative position when its corresponding finger is again operated to knitting position.

14. In yarn changing mechanism in a circular kniting machine, the combination of a plurality oi yarn guiding fingers each having mechanism for operating its respective finger to knitting position, means for selectively operating the mechanisms singly. means for retracting the active finger, an equal plurality of yarn pinching devices each having an operable blade co-operating therewith for pinching the yarn of its respective finger after the latter is retracted, an equal plurality of ratchet driven mechanisms for operating their respective blades to operative position, an equal plurality of engagingly operated slide bars each adapted to engage a certain one of said ratchets in the operative movement of the bar, a cam having vertical movement to an equal plurality of varied operating planes or levels in each of which the cam engagingly operates a certain one of said slide bars, cam controlling means for eflecting the vertical movement of u the cam to the plane or level to operate the mechanism associated with the operable blade corresponding to the active finger, means for disengaging the ratchet after its associated mechanism is operated, means for reversely operating said mechanism when its associated ratchet is disengaged, a member which is connectedly operated by the slide bar controlling the movement of the blade corresponding to the active finger, into position to engage a second member of the operating mechanism of said finger when the latter is retracted for the purpose of preventing reverse movement of the bar and which is adapted to be released from said engagement by the movement of the mechanism operating said finger to knitting position thereby rendering the bar free to move reversely, and resilient means for operating the bar reversely when said engagement is broken.

15. In a circular knitting machin having a circle 01' vertically arranged knitting needles operating in stationary slots and a suitably supported central rotating member for operating the needles and radially arranged dial knittin needles operating in stationary horizontal slots provided outside of said circle and a rotating dial cam plate suited for projecting the dial needles progressively inside of said circle to receive yarn from a source of supply, the combination in yarn changing mechanism comprising a relatively stationary cam having vertical movement to a plurality of varied operating planes or levels, means for controlling the vertical movements of the cam in required order, an equal plurality of retractively tensioned revolving yarn guiding fingers suitably positioned within said circle to guide their respective yarns from a source of supply to the projecting dial needles when the fingers are moved to knitting position, each finger having mechanism which is engagingly operated by said cam when the latter is moved to a predetermined plane or level, for operating it to knitting position, a pawl associated with each mechanism for keeping the retractively tensioned finger in knitting position after the engagement of its respective mechanism with the cam is terminated, revolving mechanism operated by said cam which is adapted to disengage the pawl corresponding to the active finger when the cam is moved to a plane or level other than that in which the finger was operated to knitting position whereby the retraction of the active finger is effected, an equal plurality of independent yam pinching devices revolving with the fingers and suitably mounted within said circle of needles, each device having an operable blade cooperating therewlth to pinch the withdrawn yarn of its associated finger after the latter is retracted. revolving mechanism operated by said cam for operating the blade associated with the aforesaid actlve finger to operative position, and means operatively controlled by said cam for retracting the operated blade.

ALBERT KRASA. 

